Welders Helmet rear Lense Cover Features: Rear lens cover Auto-Darkening Filter Lens Shade 9-13 Variable Shade Adjustable Sensitivity and Delay Controls Australian Standards Compliance Medium Impact Suitable for use with CIGWELD Magnification Lenses Grinding and Welding Modes Shade Variable: # 9-13 Filter Lens dimensions: 110 X 90 X 90mm Viewing area dimensions: 98 X 43mm Reaction time: 1/30,000 second Sensors: 2 optical sensors Power Supply: Solar cells/Battery back up Operating Temperature: - 5C to + 55 C On/Off Control: Automatic Specficiations: Size: 5mm - B1005